Variable buffer



5 heets-sh 2 3mm Victor 11mm WWO Oct. 26, 1943. v. F. LUCHT VARIABLE BUFFER Filed May 18, 1942 3 Sheets-Sheet 3 Victor E Lu E1111 preceding figure.

to'the end position of-pis tont l'.7-; I v 'tion corresponding to the endpos'ition of the Patented Dot. 26,1943 I Application a 13, 1942 seen-se an SCIaims. (miss-94); I

v KG ted"underlthe' actlof M nn 3 I A a e fiedApril 30,1925; 370

; The invention .describedherein may be manuiactured and used by or fora-the Government for governmental purposes; withoutv the paynrientv to me of any royalty thereonr'i" -L This invention relates rto ajbufierj, assembly particularly for use witha gun;

:An" object of this invention is to prov de a buffer .which'produces the sameequal. controllingeffect'on a movable gun part irrespectiile of the' firing .position .of the gun',.:i. e.,-- the same;

effect is produced in maximum-elevation as in maximum depression. i 1 Another object of this invention is to, provide:

a compact and simple arrangement of parts in a bufier mechanism'and wherein the buffer effectiproducedis constant irrespective of whether the gun is fired atmaximuin'Ielevationfor at maximum depression."

The specific nature of the invention as well as other objects -andadvantages will clearly appearfrom a description of a preferredembodim'ent as shown in the. accompanying drawings in which;

Fig. 1

Figs. 2, 3, 4, is and 6 are sectional views taken substantially on corresponding lines in- Fig.1. 1

the direction F -*1 of Fig. 1.

Fig. 8'is' aside elevation of- Valve body 12. i Fig. 9is aside elevation of the Valve body l2, taken onthe side opposite that shown in the Fig, 10 is a plan viewof the Valve body-12. v Fig. 11 discloses a section-of a modified vstructure which is similar to the section shown in Fig. but with the piston 13' displaced a small amount from its end position. a I

Fig. 12 is a side elevation'vi'ew of a 'portionof the modified sleeve shown in Fig-11.; The

point indicated by A in this figure corresponds piston as shown in Fig. 3.

Fig. 13 discloses a fragmentary sectional View through the center of the bufier mechanism when the piston i3 is about to comeinto cooper-- ating relationship with buffer H as the piston l3 returns from one of'its extreme positions (not shown) to the other extreme position shown'in discloses a longitudinal."fragmentary section through the 'center' 'oi the bufier mecha-g nism when the piston Kids at one 'endof itsre- 1 'coilstroke' 1 =1 said end positen'ds to move 'at'variablspeed eventhough constant forces 'are'appliedto the piston as it'm'ove's.

Fig. .7 is an'endview taken substantially in! 0 the valve body shoulder 12c and adjustable s cre tween valve body l2 and buffer I l.

' mounted bufier ,"l l and :which contains :therein T mova-ble' piston-i3 attachable to a movable. gun. i part (notshown). atthe upper end of'Fi'g. 1;-'and Y a yamovable valve body l2 springbiasedand slid;- ably-mounted in the bufierllp- Sleeve Ztof steel 1 or-bronze and preferably of "steel isficentrally i i mountedwimcylinder ini-"and'providesa bearing". 1'0 surface for outer (fp'ortionsjfof "piston headl3c. "soit-antifrictiongrnaterial. Piston-l3besidesbea ing-" disposedin i sliding relationship tojstatidn :arysleevehiliL gslides:over stationary bufierll.

' withoil or other similanfluid from a suitablelreservoir ':(-noti'fshown) "Piston apertures lBbYalllow relative unrestricted fluid" passage to.-.=opposite sides': ofpiston'hea'dimc-as the piston 13 moves -izi :sle'eve' Eh-113m in the modification shown in Figs. 11 and12 diznmetrically"disposedholes 2017' {I 1 are designed so' as ,toofier a variable apertureenters piston hollow-portion I311 with a relative;

-||a.- The valve bodynot'ch 12a is normally:

1 "movement: of yalvei body aligned position the amount of" oil flow thereclosing i-cylinder fill carryingaithe stationarily:

The piston outer portions l3c .'are preferably of 1 The siinclosing i cylinder 10. is maintainedfilled i in sleeve "20," cooperate with solid pistonrhea'cljltff to opposite' sids'of pistonhea'd each one' of the'twotdiametricallyfdisposecl sleeve holes 20bit of, such dimensions whereby the piston headl c W'h'en "piston; 13 is stationary or when buffer: l;l

initial velocity (ina -direction indicated by the arrow in Fig. 11) below apredeter'mined value, correspondingg -to theinitial-yelocity at maximum j' gun elevation, the "fluid in" piston hollow portion l'tw'has' free access to the fluid surroundin bufier H, dueto the fact that a valve body notch I211 is aligned with bufier port Ha whereby i fiuid may flow fromvpiston hollow portion [3a through i I,

buffer passage 1 lb,'valve body hollow portion [2b, 11,]

valve body notch I251, and throughbuffer port" 'aligned withbuffer port lld,'*as'in Fig. 1, due 'to coil compression 'spring M, which'acts betwee l5. Bufier, shoulder- 12h limits llongit g Va e'body notch 12a is so, designedlthat {when is in its normal through is constant regardless of the angular fpo sition of valve body' l2 with respect .to bufier l i. e., it is not necessary to provide guid be The fiuidpressure inpiston chamber l3a va ries as a function of the initial velocity imparted t the piston I3 in its motion indicated by the arrow in Fig. 1. And, also the velocity imparted to piston I3 due to movement of gun part (not .shown) is a function of the angleof fire of the effects for the variable initial velocities imparted to piston l3 at the different angles of fire. example, in applicants particular gun, the initial relative velocity with which. piston [3 comes into cooperating position with fixed bufier H increases with depression angles and decreases with elevation angles. Valve body l2 =is normally held-in the open position by spring l4, the tension of which is regulated by screw i5. Buffer port llcl allows fluid flow therethrough as valve body l2 moves. The ports and channels from piston chamber [3a to the space surrounding piston I3 that the valve body I2 is fully closed when firing at maximum depression; when firing at maximum depression, most of the oil leakage is -between :1

the inner walls of piston l3 and adjacent loosely For angles of fire between biased so as to provide variable compensatory restricted fluid flow occurs through buffer port I I initially enters the hollow portion of piston IS in "a direction indicated by the arrow in Fig. l and as the piston moves in that direction when in surrounding'relationship to bufier ll. When and a the piston l 3 moves in a'direction opposite to that indicatedby the arrow in Fig. 1 valve l2 remains open at all angles of fire and relative un- Ha, as the bufier ll separates'from surrounding relationship to piston. 13;. and, when piston l3 moves out of surrounding relationship to buiier H, of course, fluid may flow directly into piston I hollow portion Itc.

maximum elevation and maximum depression the valve body I! closes buffer port lIain-propor- The cylinder I0 is closed at .its bottom end in tional relationship.

Fig. 1 by a screw threadedly mounted cover 16 thereon with rings of fluidtight Epacking 23 and.

tion'between' the adjusting screw l5 and bufier .The upper end of cylinder 10 shown in Fig. l

is closedby means (not shown), but in a manner similar to that shown above for the lower end and an oil breathing'chamber or'reservoir (not shown) is connected so as to maintain cylinder H! full of oil. I I j l I It is noted that the notch [2a in valve body l2 has an'opening approximately equal to thediameter of port 1 la, and that the notch extend the. full diameter of'port Ha so that the valve body 92 closes buffer port Ila after the valve body is moved a distance approximately equal to the diameter of port I la. Other possible notch configurations might be suggested to one'skilled in the:

art and may function equally well,,butthe particular notch configuration asdisclosed by applicant is his preferred embodiment and does not require'guide members for preventing rotation of'valve body l2. i

This invention relates primarily to operating forces and means placed in operation when bufier The adjusting screw l I claimi 1 i In a-bufier assembly, a cylinder, a buffer centrally mounted in the cylinder, a piston slidable in the cylinder and having a hollow. portion adapted to receive thebuiier, said buffer having a passageway extending therethrough in communication withfthe piston hollow portion, and a pressure responsive valve. in the buffer passage- -way intermediate itsends and controlling a pasa passageway extending therethrough'in communication with the piston hollow portion, a pressure responsivevalve in the buifer passageway intermedi'at'e its ends and controlling the passage of fluid between the buffer passageway and the buffer "end of the cylinder, and means for varying the operable pressure range of the valve. 7

3.111 a bufierr assembly, a cylinder, a buffer centrally mountedin .the'cylinder, a piston slidable in the cylinder and'having a hollowportion adapted to receive the bufier, said buffer having a passageway extending therethrough in communication with the piston hollow portion, a cover for one end of the cylinder, an adjusting screw centrally mounted on the cover, a valve body slidably mounted in the bufler passageway intermediate the ends ofsaid passageway and controlling a passage of fluid between said passageway and the buiier end ofthe cylinder, and resilient means disposed between the adjusting screw and valve body..." i

4. A fluid cylinder, a fluid piston having a hollow portion and slidably mounted in the cylinder, a coverior one end of the cylinder and having ,an: aperture therethroug'h, a buffer having a flange and extending through the cover aperture into the piston hollow portion, said buffer having'a longitudinal passage therethrough, a valve body slidable in the. buffer longitudinal passage,

a nut threaded on the cover and pressing the buffer flange against the cover, an adjustment 5."I'he same as inclaim 4 and a second 111st material between the second nut and the adjv stvid'ron F. LUCHT. 

